Primarily because of their thermal stability, it has been recognized that polyfluoroalkylether fluids have a great potential for use as lubricants. For example, the prior art discloses greases formulated from such fluids and thickeners such as a fluorinated copolymer of ethylene and propylene or a polymer of tetrafluoroethylene. These greases have proven to be useful as lubricants over a wide range of temperatures, e.g., as low as -40.degree. F. and as high as 600.degree. F. Although the greases have been found to possess superior lubricating characteristics, their utility has been limited as a lubricant for ferrous metals under conditions of high humidity and mild temperatures (below 212.degree. F.). Their utility has also been limited by their inability to provide anticorrosion properties when employed as lubricants for ferrous metals under conditions of high temperature (above 450.degree. F.).
In U.S. Pat. No. 4,132,660, issued to us on Jan. 2, 1979, there is disclosed a grease composition containing a perfluorinated polyalkylether base fluid and a fluorine-containing benzoxazole as a rust and corrosion inhibitor. While the patented grease composition is effective in overcoming the above-discussed problem, it would be desirable to have other greases possessing outstanding antirust and anticorrosion properties.
It is an object of this invention, therefore, to provide a new and improved grease composition based upon a polyfluoroalkylether fluid.
Another object of the invention is to provide a grease composition possessing antirust properties while lubricating ferrous metals under conditions of high humidity and mild temperatures.
A further object of the invention is to provide a grease having anticorrosion properties while lubricating ferrous metals in high temperature environments.
Other objects and advantages of the invention will become apparent to those skilled in the art upon consideration of the accompanying disclosure.